1. Field
The present invention relates to a robot cleaner, and, more particularly, to a robot cleaner configured to achieve an improved cleaning performance.
2. Description of the Related Art
A cleaner is an appliance to eliminate dirt and clean a room. Generally used is a vacuum cleaner to suction dirt by use of a suction force generated from a low-pressure unit.
Recently, the development of a robot cleaner is underway. The robot cleaner eliminates dirt from the floor by a self-running function thereof without a user's labor.
One example of the robot cleaner is disclosed in Korean Patent Laid-Open Publication No. 10-2006-0027701.
The robot cleaner disclosed in the above Publication includes a body case having a dust or dirt suction hole and an air-discharge hole, a fan motor installed in the body case to generate a suction force, a filter container installed in front of the fan motor and receiving a filter to collect dust or dirt suctioned by operation of the fan motor, a suction head provided at the bottom of the body case and connected with the filter container through a connection tube to suction dust or dirt from the floor, a brush rotatably disposed in the suction head to sweep up dust or dirt on the floor, and an air-purifying filter installed in the body case to purify air, suctioned into the robot cleaner together with the dust or dirt, prior to being discharged through the air-discharge hole.
The most important factors having an effect on a cleaning performance of the robot cleaner are the suction force generated by the fan motor and the brush mounted at a side of the suction hole. The greater the suction force, the greater the cleaning performance. Also, when suctioning dust after scattering upward the dust by use of the brush, an improved cleaning performance can be anticipated.
However, the robot cleaner has a problem of not being able to adopt a large-size fan motor providing a high suction force because it should be configured to have a small size and low height to clean under furniture, such as a sofa, and has only a restricted battery capacity.
As a result, the robot cleaner generally uses a fan motor having a significantly lower capacity (approximately 30˜100 W) than a capacity (approximately 600 W) of a conventional vacuum cleaner, and has a limit to suction heavy dust into the filter by use of the low-capacity fan motor.
More specifically, in operation of the robot cleaner to deliver dust, scraps, etc. on the floor to the filter, after the dust is scattered upward from the floor by the brush, the scattered dust is suctioned into and collected by the filter mounted in the filter container by passing through the suction head and the connection tube extending vertically from the suction head under operation of the fan motor. However, since the low-capacity fan motor generates an inferior suction force, it is difficult for the robot cleaner to exhibit a satisfactory cleaning performance.
In the robot cleaner having the low-capacity fan motor, it is necessary to reduce a sectional area of the suction hole for the sake of strengthening the suction force. However, this deteriorates an ability to collect bulky or various shapes of dust. Also, when increasing the sectional area of the suction hole to improve the cleaning performance of the robot cleaner by a sweeping operation using the brush, there is a problem of a deterioration in the suction force generated by the fan motor.